Current high performance gas turbine engines utilize various techniques to maximize performance of the gas turbine engine. One effect of the performance maximization techniques is an increase in the temperature of fluid exiting a high pressure compressor section of the gas turbine engine. The fluid exiting the high pressure compressor section is referred to as a high pressure compressor discharge and is discharged into a combustor section. The increased temperature of the high pressure compressor discharge may exceed optimum cooling temperatures of cooling air for at least one stage of a high pressure turbine.
Some existing gas turbine engines cool at least the first stage of the high pressure turbine by redirecting a portion of the high pressure compressor discharge onto the first stage of the high pressure turbine. As the discharge air is cool, relative to the temperature of the turbine stage, this provides a cooling effect. When the temperature of the high pressure compressor discharge air exceeds optimum cooling temperatures of the turbine stage, the cooling capability of the discharge air is reduced, and the workable lifespan of the cooled turbine stage may be correspondingly reduced.